217 lines
7.1 KiB
C
217 lines
7.1 KiB
C
/****************************************************************************
|
|
* sched/signal/sig_deliver.c
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership. The
|
|
* ASF licenses this file to you under the Apache License, Version 2.0 (the
|
|
* "License"); you may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
* License for the specific language governing permissions and limitations
|
|
* under the License.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <sys/types.h>
|
|
#include <signal.h>
|
|
#include <unistd.h>
|
|
#include <sched.h>
|
|
#include <string.h>
|
|
#include <debug.h>
|
|
|
|
#include <nuttx/irq.h>
|
|
#include <nuttx/arch.h>
|
|
#include <nuttx/signal.h>
|
|
|
|
#include "signal/signal.h"
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: nxsig_deliver
|
|
*
|
|
* Description:
|
|
* This function is called on the thread of execution of the signal
|
|
* receiving task. It processes all queued signals then returns.
|
|
*
|
|
****************************************************************************/
|
|
|
|
void nxsig_deliver(FAR struct tcb_s *stcb)
|
|
{
|
|
/* Save the errno. This must be preserved throughout the signal handling
|
|
* so that the user code final gets the correct errno value (probably
|
|
* EINTR).
|
|
*/
|
|
|
|
int saved_errno = get_errno();
|
|
int16_t saved_errcode = stcb->errcode;
|
|
|
|
FAR sigq_t *sigq;
|
|
sigset_t savesigprocmask;
|
|
sigset_t newsigprocmask;
|
|
sigset_t tmpset1;
|
|
sigset_t tmpset2;
|
|
irqstate_t flags;
|
|
|
|
/* Loop while there are signals to be delivered */
|
|
|
|
for (; ; )
|
|
{
|
|
/* Test if this task is already handling a signal (we don't permit
|
|
* nested signals on the same thread).
|
|
*/
|
|
|
|
flags = enter_critical_section();
|
|
if ((stcb->flags & TCB_FLAG_SIGNAL_ACTION) != 0)
|
|
{
|
|
/* Yes.. then we must wait for the signal handler to return */
|
|
|
|
leave_critical_section(flags);
|
|
break;
|
|
}
|
|
|
|
/* Remove the signal structure from the head of the sigpendactionq. */
|
|
|
|
sigq = (FAR sigq_t *)sq_remfirst(&stcb->sigpendactionq);
|
|
if (sigq == NULL)
|
|
{
|
|
/* All queued signal actions have been dispatched */
|
|
|
|
leave_critical_section(flags);
|
|
break;
|
|
}
|
|
|
|
/* Indicate that a signal is being delivered */
|
|
|
|
stcb->flags |= TCB_FLAG_SIGNAL_ACTION;
|
|
|
|
sinfo("Deliver signal %d to PID %d\n",
|
|
sigq->info.si_signo, stcb->pid);
|
|
|
|
/* Add the signal structure to the sigpostedq. NOTE: Since signals
|
|
* are processed one at a time, there should never be more than one
|
|
* signal in the sigpostedq
|
|
*/
|
|
|
|
sq_addlast((FAR sq_entry_t *)sigq, &(stcb->sigpostedq));
|
|
|
|
/* Save a copy of the old sigprocmask and install the new
|
|
* (temporary) sigprocmask. The new sigprocmask is the union
|
|
* of the current sigprocmask and the sa_mask for the signal being
|
|
* delivered plus the signal being delivered.
|
|
*/
|
|
|
|
savesigprocmask = stcb->sigprocmask;
|
|
sigorset(&newsigprocmask, &savesigprocmask, &sigq->mask);
|
|
nxsig_addset(&newsigprocmask, sigq->info.si_signo);
|
|
stcb->sigprocmask = newsigprocmask;
|
|
|
|
#ifndef CONFIG_BUILD_FLAT
|
|
/* In the kernel build this has to be handled differently if we are
|
|
* dispatching to a signal handler in a user-space task or thread; we
|
|
* have to switch to user-mode before calling the task.
|
|
*/
|
|
|
|
#ifdef CONFIG_SIG_DEFAULT
|
|
/* The default signal action handlers, however always reside in the
|
|
* kernel address space, regardless of configuration.
|
|
*/
|
|
|
|
if (nxsig_isdefault(stcb, sigq->info.si_signo))
|
|
{
|
|
/* Leave the critical section before calling the handler */
|
|
|
|
leave_critical_section(flags);
|
|
(*sigq->action.sighandler)(sigq->info.si_signo, &sigq->info,
|
|
NULL);
|
|
}
|
|
else
|
|
#endif
|
|
if ((stcb->flags & TCB_FLAG_TTYPE_MASK) != TCB_FLAG_TTYPE_KERNEL)
|
|
{
|
|
siginfo_t info;
|
|
|
|
/* The sigq_t pointed to by sigq resides in kernel space. So we
|
|
* cannot pass a reference to sigq->info to the user application.
|
|
* Instead, we will copy the siginfo_t structure onto the stack.
|
|
* We are currently executing on the stack of the user thread
|
|
* (albeit temporarily in kernel mode), so the copy of the
|
|
* siginfo_t structure will be accessible by the user thread.
|
|
*/
|
|
|
|
memcpy(&info, &sigq->info, sizeof(siginfo_t));
|
|
|
|
/* Leave the critical section before calling the handler */
|
|
|
|
leave_critical_section(flags);
|
|
up_signal_dispatch(sigq->action.sighandler, sigq->info.si_signo,
|
|
&info, NULL);
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
/* The kernel thread signal handler is much simpler. */
|
|
|
|
leave_critical_section(flags);
|
|
(*sigq->action.sighandler)(sigq->info.si_signo, &sigq->info,
|
|
NULL);
|
|
}
|
|
|
|
/* Indicate that a signal has been delivered */
|
|
|
|
flags = enter_critical_section();
|
|
stcb->flags &= ~TCB_FLAG_SIGNAL_ACTION;
|
|
|
|
/* Restore the original sigprocmask.
|
|
*
|
|
* What if the signal handler changed the sigprocmask? Try to retain
|
|
* any such changes here.
|
|
*
|
|
* REVISIT: This logic is imperfect. It will fail to detect bits set
|
|
* in the current sigprocmask that were already set by newsigprocmask.
|
|
*/
|
|
|
|
nxsig_xorset(&tmpset1, &stcb->sigprocmask, &newsigprocmask);
|
|
sigandset(&tmpset2, &stcb->sigprocmask, &tmpset1);
|
|
nxsig_nandset(&tmpset1, &savesigprocmask, &tmpset1);
|
|
sigorset(&stcb->sigprocmask, &tmpset1, &tmpset2);
|
|
|
|
/* Remove the signal structure from the sigpostedq */
|
|
|
|
sq_rem((FAR sq_entry_t *)sigq, &(stcb->sigpostedq));
|
|
leave_critical_section(flags);
|
|
|
|
/* Now, handle the (rare?) case where (a) a blocked signal was
|
|
* received while the signal handling executed but (b) restoring the
|
|
* original sigprocmask will unblock the signal.
|
|
*/
|
|
|
|
nxsig_unmask_pendingsignal();
|
|
|
|
/* Then deallocate the signal structure */
|
|
|
|
nxsig_release_pendingsigaction(sigq);
|
|
}
|
|
|
|
/* Restore the saved errno value */
|
|
|
|
set_errno(saved_errno);
|
|
stcb->errcode = saved_errcode;
|
|
}
|